/*      $NetBSD: prepargs.c,v 1.1.1.1 2016/01/13 03:15:30 christos Exp $        */

/* Parse arguments from a string and prepend them to an argv.

  Copyright (C) 1999, 2000, 2001, 2002 Free Software Foundation, Inc.

  This program is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation; either version 2, or (at your option)
  any later version.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  02111-1307, USA.  */

/* Written by Paul Eggert <[email protected]>.  */

#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include "prepargs.h"
#include <string.h>
#include <sys/types.h>
#include <xalloc.h>

#include <ctype.h>

/* IN_CTYPE_DOMAIN (C) is nonzero if the unsigned char C can safely be given
  as an argument to <ctype.h> macros like "isspace".  */
#ifdef STDC_HEADERS
# define IN_CTYPE_DOMAIN(c) 1
#else
# define IN_CTYPE_DOMAIN(c) ((c) <= 0177)
#endif

#define ISSPACE(c) (IN_CTYPE_DOMAIN (c) && isspace (c))

/* Find the white-space-separated options specified by OPTIONS, and
  using BUF to store copies of these options, set ARGV[0], ARGV[1],
  etc. to the option copies.  Return the number N of options found.
  Do not set ARGV[N].  If ARGV is zero, do not store ARGV[0] etc.
  Backslash can be used to escape whitespace (and backslashes).  */
static int
prepend_args (char const *options, char *buf, char **argv)
{
 char const *o = options;
 char *b = buf;
 int n = 0;

 for (;;)
   {
     while (ISSPACE ((unsigned char) *o))
       o++;
     if (!*o)
       return n;
     if (argv)
       argv[n] = b;
     n++;

     do
       if ((*b++ = *o++) == '\\' && *o)
         b[-1] = *o++;
     while (*o && ! ISSPACE ((unsigned char) *o));

     *b++ = '\0';
   }
}

/* Prepend the whitespace-separated options in OPTIONS to the argument
  vector of a main program with argument count *PARGC and argument
  vector *PARGV.  */
void
prepend_default_options (char const *options, int *pargc, char ***pargv)
{
 if (options)
   {
     char *buf = xmalloc (strlen (options) + 1);
     int prepended = prepend_args (options, buf, (char **) 0);
     int argc = *pargc;
     char * const *argv = *pargv;
     char **pp = (char **) xmalloc ((prepended + argc + 1) * sizeof *pp);
     *pargc = prepended + argc;
     *pargv = pp;
     *pp++ = *argv++;
     pp += prepend_args (options, buf, pp);
     while ((*pp++ = *argv++))
       continue;
   }
}